I totally understand your problem. I too, suffer from the same thing. First, I like to congratulate you on your surgery, good for you! Your surgery caused your body to digest and process foods in a different way. I think the foul smell might be coming from bacteria overgrowth in you intestines. An overgrowth of bacteria, either from you mouth or intestines, will cause a foul smell. If you body is causing food to travel slower or be malabsorbed this along with other caused will cause bacteria to multiply into more bacteria than your intestines need. A strong course of antibiotics for at least 2 weeks might help. I would suggest an antibiotic that stays in the gut, instead of being absorb into your blood stream, would work best. Try Flagly or Neomycin. I hope this will help.
I agree with MedicalMom that it is probably an overgrowth of yeast (bad bacteria) in your gut. However, I do not agree that you should take an antibiotic to get rid of it. Antibiotics kill all the good bacteria in your gut making the yeast floish. Buy a little, tiny book that is easy to read by Dr. Don Colbert called, The Bible Cure for Yeast and Candida. You can probably get it on his web site. Follow the instructions. In the meantime, purchase a probiotic called Primal Defense by Garden of Life. It's the best probiotic on the market. Get the capsules. Not the powder or the tablets. Also, by Omega-Zyme by Garden of Life. It's a digestive enzyme. Take it with your food. Cut out all forms of sugar, including fruit and fruit juice. Cut out all fermented foods like vinegar, mustard, wine, beer, bread made with yeast, etc. Cut out all refined grains like white bread, white noodles, white rice. Start eating whole, natural, foods. Oatmeal with a little stevia (the only sweetener you can have) for breakfast. Big raw salads with vinegar-free dressing (available at Whole Foods) for lunch with some whole grain yeast-free bread. Brown rice with stir-fried vegetables and chicken for dinner. Get it? Real food. And while your at Whole Foods, buy a tongue scraper. Each morning after you brush your teeth scrape your tongue. Once the balance of intestinal flora is corrected in your gut (it may take a year) this WILL go away. I promise you. By the way, I'm a Nutritionist. Good Luck.
I want to add something to what I already said. I have had a couple of patients with this problem. It is possible that it is a yeast related problem. Very possible. But it could be that your bowels aren't cleaning out (this could also be due to yeast), Go to the grocery store and buy the yogurt "Activa." Eat a little container of it every single day. Do this why you are following the yeast-free diet in the book I recommended above. In other words, eat the Activia while you are eating a diet that consists of whole, natural, foods, omitting those foods that feed yeast, just in case it is an imbalance of good and bad bacteria that is causing this. I knew one girl who was beautiful. Truly she looked liked a model. But she had this problem for years. She had no idea that she was constipated because she had a bowel movement every day. But, I came to find out that her bowel movements were not "normal and healthy." A normal, healthy bowel movement is the shape of your colon and 2 to 3 feet in length. Her colon was backed up. It was due to a yeast problem that she didn't realize she had. And her breath smelled terrible and everybody told her so. This went on for years and years. Then, she went off all dairy and all animal flesh. She also got off all junk food. She ate only whole, natural, foods. She became a vegan. (See Dr. Don Colbert's book, "What Would Jesus Eat") She also started taking a probiotic. I don't know which one (Primal Defense Ultra capsules were not on the market yet or I would have told her to take that.) After following this healthy vegan diet very strickly, taking a probiotic, and avoiding foods that feed yeast, she got rid of the problem. It took her 7 months. Not only did her breath get sweet but her skin glowed and her eyes were very white. She also said she felt better than she ever had in her life. As a result, she still eats this way, and it's been a few years now. If your eating healthy, whole, natural foods and having 1 healthy bowel movement each day, and your intestinal flora is balanced, you won't have any more bad breath. If the Activia doesn't help move your bowels (it takes 2 weeks to work. then you must keep taking it) start taking the Primal Defense Ultra capsules and keep taking them whether you can tell they are working or not. If you can't lick this problem on your own by reading the book I mentioned, changing your diet, and trying these probiotics, go see a Holistic Doctor. (You will never get help from a traditional doctor) Not a new age one. A good one that works at a hospital. He'll be able to check you for yeast and treat you. Or, if you can afford it, go see Dr. Don Colbert in Florida. He's brilliant, a devout Christian, and I am absolutely, positively certain he can help you.
You never said if you have intestinal problems. Some people get very bad breath due to being lactose intolerant.
Thank you so much for your post. It was very informative. I plan to review the above mentioned material and apply this advice in hopes of finding a cure.